A labor complicated by amniotic fluid infection may have severe consequences for the mother and neonate. Two reports have indicated that women having a spontaneous abortion have an increased risk in the next pregnancy of labor complicated by amniotic fluid infection. The purpose of the proposed study is to determine the risk of amniotic fluid infection in the next pregnancy among women who had a spontaneous abortion in the immediately preceding pregnancy. The study will also determine whether an intervening normal pregnancy or a long interpregnancy interval may reduce the risk. The increased frequency of amniotic fluid infection after a spontaneous abortion may result from an unresolved maternal lower or upper genital tract infection which may have been the cause or a result of the spontaneous abortion. The proposed study will evaluate factors which may modify the relationship between spontaneous abortion and amniotic fluid infection; postabortal infection, gestational age at abortion, suction or instrument curettage after abortion, two or more successive abortions, pelvic inflammatory disease or genital tract infections before or after the abortion. These issues will be evaluated in a multi_hospital, case-control study of 1360 women with amniotic fluid infection in their present pregnancy compared to a equal sized control group. The cases will be identified at six collaborating hospitals in King County, WA which treat 80% of the women delivering in the county. Controls will be frequency matched to cases for hospital and month of delivery. Study participants will have a medical record review of their present pregnancy and a detailed structured interview focusing on their prior pregnancies. The proposed study may determine that women having spontaneous abortions may need to be identified, evaluated for genital tract infections, and possibly treated, before attempting future pregnancies.